1. Technical Field
The present disclosure relates generally to illuminating devices, in particular, an illuminating device having a point light source.
2. Description of Related Art
Currently, light emitting diodes (LEDs) have been widely employed in various illuminating devices to replace cold cathode fluorescent lamps (CCFLs) due to their excellent light emission spectrum. The emitted light from a LED usually has a taper shaped distribution, and the intensity of the light decreases from a central axis of the taper to an outer thereof. To provide a uniform surface light device, a light diffusing unit (e.g., a light guide plate) is provided to diffuse the light emitted from the LED. However, as a common issue with the light guide plates, total reflection usually occurs at surfaces of the light guide plate, resulting in a very low emission efficient of the surface light device.
Therefore, there is a desire to provide a new surface light device having improved light emission efficiency.